In today's rapidly changing world of work, continuous learning, training and skill development activities by workers are increasing in importance. Concurrently, the average age of workers is also increasing. Some prior research suggest that older workers do not participate in learning and development activities as much as younger workers, and an important contributing factor to this age effects is a decline in self-efficacy (or self confidence) for career-relevant learning and skill development with age. Self-efficacy is a critical construct to understand in relation to aging and learning activity because: (a) it has been consistently linked with participation and performance in training and development activities; (b) important antecedents of self-efficacy are negatively related to age and; and self-efficacy is a person characteristics which can be changed or improved (as opposed to relatively immutable characteristics such as personality or intelligence). Given the high potential payoff of studying this variable, a targeted, in-depth analysis of the construct in relation to worker age will be done. Surveys will be administered to a large, age-diverse sample of employed adults at three points in time across a period of 13 months. The research will examine worker age in relation to: (a) self-efficacy for career-relevant learning and development, (b) organizational, social, psychological and physiological antecedents of self efficacy, and training and development attitudes, intentions and behavior. The hypothesized sequence of relations is: age greater than antecedents greater than self-efficacy greater than attitudes/intentions greater than participation. Therefore, self- efficacy and its antecedents are expected to be significant mediators of the understanding of relationship among age, self-efficacy and skill development behavior constructs, but also some practical implications regarding how to enhance learning and development behavior by older workers. Additionally, the research will provide a system of assessment tools, complete with normative, psychometric, and validity data, which can be used to measure the constructs in other settings as part of diagnostic, organizational and employee development interventions and research.